A video showing an elderly priest slapping a baby who cried at his baptism has caused outrage among viewers.

It is not known who the French priest or the family were, but the video uploaded to Reddit shows the priest speaking affectionately to the baby, who is crying as he is held by his mother before the baptism.

In an apparent attempt to quieten him after repeatedly saying 'Calm down', he suddenly slaps him across the face, leaving the family stunned. As the father attempts to take the child the priest resists and attempts to muffle the child's cries. Witnesses can be heard saying, 'He's afraid, let go.'

Another witness appears to remonstrate with the priest.

Comments on social media under the story include one from fallforantiwords, who said: 'Anyone know what city/province this takes place in? More specifically what church this is in? This should be reported to the catholic clergy and he should be banned!'

Escarfangorn said: 'That would end with that priest on the ground the moment he'd dare to hurt my kid.'

Cjbeams said: 'Yeah. In reality he just physically abused a baby. I hope he's in jail. The dad's face when it happens as well, he's clearly already uncomfortable.